Catheters are used in various interventional procedures for delivering therapeutic means to a treated site (e.g., body organ or passageway such as blood vessels). In many cases, a catheter with a small distal inflatable balloon is guided to the treated site. Once the balloon is in place it is inflated by the operator for affixing it in place, for expanding a blocked vessel, for placing treatment means (e.g., stent) and/or for delivering surgical tools (e.g. knives, drills etc.) to a desired site. In addition, catheter systems have also been designed and used for retrieval of objects such as stents from body passageways.
Rapid-exchange catheters have been developed for intravascular use and are routinely used for angioplastic treatment of stenosed vessels in patients.
Rapid exchange (“monorail” or RE) catheters typically comprise a relatively short guide wire lumen provided in a distal section thereof, and a proximal guide wire exit port located between the catheter's distal and proximal ends. This arrangement allows exchange of the catheter over a relatively short guide wire, in a manner which is simple to perform and which can be carried out by a single operator. Rapid exchange catheters have been extensively described in the art, for example, in U.S. Pat. Nos. 4,762,129, 4,748,982 and EP0380873.
Rapid exchange catheters are commonly used in Percutaneous Transluminal Coronary Angioplasty (PTCA) procedures, in which obstructed blood vessels are typically dilated by a distal balloon mounted on the catheter's distal end. A stent is often placed at the vessel's dilation zone to prevent reoccurrences of obstruction therein. The dilation balloon is typically inflated via an inflation lumen which extends longitudinally inside the catheter's shaft between the dilation balloon and the catheter's proximal end.
Published International Application Nos. WO 2005/102184 discloses a catheter having a rollable expandable element. Published International applications, WO 2007/004221, WO 2007/042935, WO 2008/004238 and WO 2008/004239, all five published international applications are incorporated herein by reference in their entirety for all purposes, disclose various types of catheters and catheter systems having intussuscepting balloon-like inflatable members which may be used, inter alia, to treat plaque by balloon inflation while efficiently and safely collecting plaque debris and other particulate matter from the lumen of pathologically-involved blood vessels and to remove such particles and particulate matter from the blood vessel.
WO 2008/004238 discloses several types of rapid exchange catheters having an intussuscepting balloon-like inflatable member which may be used for treating plaque in stenosed vessels and for collecting and for removing from the body plaque debris and other particulate matter resulting from the distention of the vessel wall and the compaction of plaque during the inflating of the balloon within the blood vessel.
While the various types of rapid exchange catheters with intussuscepting balloons disclosed in WO 2008/004238 may be efficiently and safely used for treating patients, their construction is based on the use of a segmented tubular inner conduit having several segments. Some segments of the inner conduit are slidably disposed within other segments of the inner conduit in order to enable the distal part of the inner conduit to move proximally during the intussuscepting of the balloon. In order to keep the segmented inner conduit sealed, WO 2008/004238 discloses the use of sealing gaskets designed to withstand the inflation pressure of the balloons. While sealing gaskets are well known in the art their use may pose several technical difficulties, due mainly to the fact that the implementation of sealing gaskets may require expensive and time consuming construction techniques as well as the use of time consuming and expensive testing and quality control procedures. This is especially challenging when the diameters of inner conduit and of the necessary gaskets are relatively small.
While the cavity forming intussuscepting balloons are quite efficient for trapping debris and/or particulate matter or secretions from the treated site, the construction of a movable inner conduit that slides within an outer conduit and the operation of mechanisms to move the inner conduit as combined with an intussuscepting balloon are fairly complex and require expertise to construct and to operate. In particular rapid exchange (monorail) catheters with intussuscepting balloons are not simple to construct.
International published applications WO 08/004238 and WO 08/004239 disclosed a sleeve collecting device having a tube with a sleeve suitable for passage of a debris collecting catheter therethrough. However, such sleeve devices are separate from the debris collecting catheter, require the handling and operating of two separate devices (a sleeve collecting device and a separate debris collecting catheter which is separate from the sleeve device that are longitudinally or axially freely movable relative to each other). The debris collecting catheter is based on an intussuscepting balloon which is first inserted through the lumen of the sleeve device and then operated at the treatment site and only after the capturing of the debris by the catheter the catheter is withdrawn proximally to enter the sleeve of the separate sleeve device.
U.S. Pat. No. 5,092,839 to Kipperman discloses a system including an angioplastic balloon catheter which is movably disposed within a hollow thrombectomy catheter. The thrombectomy catheter has a distal end which may be expanded by inflating the balloon catheter. However, the balloon catheter is axially (longitudinally) movable with respect to the thrombectomy catheter and the system requires moving the balloon catheter distally outside of the thrombectomy catheter in order to perform angioplasty on the lesion followed by proximal movement of the balloon catheter into the thrombectomy catheter in order to collect debris.
There is therefore a need for simple and efficient catheters capable of collecting debris and particulate matter and/or secretions at a treatment site in a body cavity.